ALBANY — It’s a $445 million gamble — with city condo and co-op owners’ holding the chips.

The city plans to send out property-tax bills to about 365,000 co-op and condo owners that will include rebates that expired nearly six months ago and that state lawmakers have yet to approve.

City Finance officials are banking on Albany retroactively approving the tax breaks — worth about $1,200 per home.

But with Gov. Cuomo signaling that Hurricane Sandy will wipe out any special state legislative session before the end of the year, a newly seated Legislature — with control of the Senate uncertain — would have to pick up the ball in January.

The city doesn’t seem worried.

“The city will send out the bills this month as originally planned, and we expect that new legislation will be acted on early in the next legislative session,” said Finance Department spokesman Owen Stone.

State Sen. Tony Avella (D-Queens) yesterday in a letter called upon Cuomo and Mayor Bloomberg to preserve current abatements by executive order — and said, without action, the average owner faces a $1,200 hit.

The June deal called for increasing abatements for owner-occupied units to as much as 28.1 percent of assessed value over three years while phasing out breaks for non-owner-occupied units.

But it was the Senate’s Republican majority that signed off on the deal, and Democrats could take control of the house if they hold on to current leads in two tight upstate races.

The rebates were created in 1997 to reduce the tax burden on co-op and condo owners, who claimed they paid far higher rates than owners of one- and two-family homes.

Because co-ops and condos are taxed as apartment buildings, they shoulder 38 percent of the city’s property-tax burden while only accounting for 24 percent of market value.

The bill that state leaders agreed to in June would modify the abatement program to redirect all benefits to owner-occupied units over three years.

That could create a mess, according to an owners advocate.

“There are lots of situations where taxes would have to be imposed retroactively, and overpayments dealt with retroactively,” predicted Jim Rheingrover, a former city Finance Department official.